At this point we know Colossus is
-Bulletproof
-Durable enough to get hit in the back of the head with a multi-ton car hurtling through the air at high speed with no damage
-Durable enough to have his powers absorbed by Rogue with no problems(Wolverine was dying)
- Punch a rather large man(frozen) so hard he shatters
- Send Wolverine hundreds of feet through the air effortlessly with enough momentum to sever a Sentinel head
But considering in X2 and X3 he had a combined total of like 2 minutes of screentime, hopefully he gets more feats in DoFP.